A growing body of documents shows microbiota produce metabolites such as short-chain fatty acids (SCFAs) as crucial executors of diet-based microbial influence the host and bacterial pathogens. The production of SCFAs depends on the metabolic activity of intestinal microflora and is also affected by dietary changes. SCFAs play important roles in maintaining colonic health as an energy source, as a regulator of gene expression and cell differentiation, and as an anti-inflammatory agent. Additionally, the regulated expression of virulence genes is critical for successful infection by an intestinal pathogen. Bacteria rely on sensing environmental signals to find preferable niches and reach the infectious state. This review will present data supporting the diverse functional roles of microbiota-derived butyrate, propionate, and acetate on host cellular activities such as immune modulation, energy metabolism, nervous system, inflammation, cellular differentiation, and anti-tumor effects, among others. On the other hand, we will discuss and summarize data about the role of these SCFAs on the virulence factor of bacterial pathogens. In this regard, receptors and signaling routes for SCFAs metabolites in host and pathogens will be introduced.